1. Field of the Invention
The present invention concerns a process for biological generation of methane.
2. Description of Related Art
Methane is an important energy carrier and a significant starting substance for the chemical industry. Methane is mostly produced from natural gas, of which it is the main component. For this purpose, fossil deposits in which natural gas and petroleum generally occur together are exploited. Such deposits are found, for example, in Russia, or also beneath the sea, for example, in the North Sea.
The availability of such fossil natural gas deposits, however, is limited. In addition, economic dependence on natural gas-producing countries can occur. Moreover, methane is present in natural gas, in addition to a number of other components, and must be separated from the secondary components by costly methods in order to obtain pure methane.
The main problem in using methane from fossil deposits, however, is the strong greenhouse potential that methane has, in the first place. In the production and transport of methane occurring as fossil fuel, a significant loss of the gas unavoidably occurs, and this fraction reaches the atmosphere as a greenhouse gas.
On the other hand, use (i.e., combustion) of fossil methane intensifies the greenhouse effect in that additional carbon dioxide reaches the atmosphere and can act accordingly as a greenhouse gas.
It is also known to recover methane-containing gases from biomass (so-called biogas process). A biogas installation for production of methane-containing gases is known from DE 10 2004 035 997 A1. Biogas generation, however, has the drawback that only very impure methane is produced, which is contaminated by carbon dioxide, water vapor, ammonia, hydrogen sulfide and other components. Moreover, sufficient biomass is not available to be able to ultimately replace fossil deposits.
Finally, it is known that several billion tons of methane in the form of methane hydrate are found on the bottom of the Earth's seas. Production of these deposits, however, is still not commercially possible and only appears to be attainable with significant cost.
The task underlying the present invention is therefore to provide an environmentally safe and cost-effective method for generation of methane that dispenses with utilization of fossil deposits.